Claiming people are being paid to riot, Republican state senators voted Wednesday to give police new power to arrest anyone who is involved in a peaceful demonstration that may turn bad — even before anything actually happened.

SB1142 expands the state’s racketeering laws, now aimed at organized crime, to also include rioting. And it redefines what constitutes rioting to include actions that result in damage to the property of others.

But the real heart of the legislation is what Democrats say is the guilt by association — and giving the government the right to criminally prosecute and seize the assets of everyone who planned a protest and everyone who participated. And what’s worse, said Sen. Steve Farley, D-Tucson, is that the person who may have broken a window, triggering the claim there was a riot, might actually not be a member of the group but someone from the other side....

There’s something else: By including rioting in racketeering laws, it actually permits police to arrest those who are planning events. And Kavanagh, a former police officer, said if there are organized groups, “I should certainly hope that our law enforcement people have some undercover people there.’’

“Wouldn’t you rather stop a riot before it starts?’’ Kavanagh asked colleagues during debate. “Do you really want to wait until people are injuring each other, throwing Molotov cocktails, picking up barricades and smashing them through businesses in downtown Phoenix?’’

This is the sort of law that is almost guaranteed to be abused and enforced in an asymmetrical manner. This is one of those laws where the "Am I comfortable giving my political opponent this sort of power" test is particularly useful. Conservatives rightly complained about the Obama Administrations asymmetric IRS scrutiny on Tea Party groups, but this law would create a far greater potential for abuse. We no longer have Sheriff Joe any more (which is one reason I don't join so many others in complaining about the election of 2016) but does anyone doubt that Arpaio would have used this law to shut down every pro-immigrant protest he could learn about in advance?